Defibrillation electrode

ABSTRACT

A defibrillation electrode having a handled metal electrode disc, to which is connected a gauze pad capable of holding a saline solution, the gauze pad and disc being held in an electrically connected state by an annular resilient holder ring. In the preferred embodiment, the gauze pad has a metal plate attached to one side thereof which is integrally connected to the holder ring. The metal plate is pressed against the electrode disc when the electrode disc is snapped into the resilient holder ring, thereby providing reliable conduction from the disc through the metal plate and gauze pad, to the patient. The combination of defibrillation electrode and attached gauze pad permits rapid and reliable defibrillation.

United States Patent 1 Moore et al.

[ Oct. 2, 1973 l DEFIBRILLATION ELECTRODE [73] Assignee: Academic Associates, Inc., Audubon,

[22] Filed: June 3, 1971 [21] Appl. No.: 149,602

Leech 128/417 3,467,863 9/1969 Karsh 128/419 D Primary Examiner-William E. Kamm Attorney-Paul & Paul [57] ABSTRACT A defibrillation electrode having a handled metal electrode disc, to which is connected a gauze pad capable of holding a saline solution, the gauze pad and disc being held in an electrically connected state by an annular resilient holder ring. In the preferred embodiment, the gauze pad has a metal plate attached to one side thereof which is integrally connected to the holder ring. The metal plate is pressed against the electrode disc when the electrode disc is snapped into the resilient holder ring, thereby providing reliable conduction from the disc through the metal plate and gauze pad, to the patient. The combination of defibrillation electrode and attached gauze pad permits rapid and reliable defibrillation.

3 Claims, 4 Drawing Figures PATENTEUUBT 2 INVENTORS. Thomas W. Moore Frank N. Dimeo Richard E. Collins pal 1 M ATTORNEYS.

.1 DEFIBRILLATION ELECTRODE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention lies in the field .of defibrillation electrodes and, more particularly,.deflbrillationelectrodes in combination with gauze pads which are soakable in a conducting solution, to provide in one apparatus the prior art combination ofa separate electrodeandxa separate solution-soaked gauze pad.

2. Description of the Prior Art External ventricular defibrillation by electric shock is a common practice in hospital cardiaccare areasand operating rooms and, to a lesser extent, -is accomplished in emergency situations outside of hospitals. The procedure for external defibrillating-by electric shock, which is well known in the art, normally provides placing two metal electrodes on the chest of the patient to cause a large quantity of electricity'to pass between the electrodes and through the patient. Such passage of electrical current in the vicinity of and/or through the heart causesresumption of normal heartbeat.

One of the most serious problems associated with electric defibrillation resides in the electrical conductivity between the electrodes used and the chest of the patient. The electrodes consist of conducting metal discs of various diameters which are normally attached to plastic or wooden handles, the metal discs being connected by suitable wiring to defibrillator apparatus which provides the necessary electrical energy. The metal discs are generally flat-surfaced, and not contoured to the body of the patient. The large currents which must flow through the electrodes and-into the patient, in order to achieve defibrillation, impose a requirement of good electrode-patient contact. In the absence of good contact, burning of the patients skin at the points of electrode contact can be quitesevere.

Further, if contact is poor enough, the electrode cur-,

rent passing through the patient may-be insufficient to cause defibrillation.

To overcome the problem of electrode-patient contact, it is common practice either to apply electrode paste to the patient, or to lay saline soaked pads on the patient, and then to press the electrodes on the pasted area or on soakedpads. The disadvantage of this present practice is that it is both awkward and time consuming to apply the paste or place thesoakedpads. The time delay in applying the electrode paste or properly placing the electrode pads is of course quite critical, since fibrillation by its nature presents an emergency situation which must be dealt .with extremely quickly. In view of this, there is presently a great need in medical practice for an external defibrillation electrode which provides the reliable electrode-patient contact which is presently obtained only by applying paste or pads prior to positioning the electrode, without having the disadvantage of requiring a time consuming-procedure.

SUMMARY OF- THE INVENTION The primary object of our invention is to provide defibrillation electrode apparatus enabling direct placement of defibrillation electrodes upon a patient, thev electrode apparatus providing a highly reliable and efficient electrical contact with the patient.

It is a further object of this invention to provide defibrillation electrode apparatus which is quickly and easily assembled, and which can beplaced in clinical use without any prior preparation of the patient, and in less time than required for use of presently existing defibrillation devices.

Accordingly, this invention comprises a defibrillation electrode having a metal electrode disc which is electrically connected to a suitable defibrillation energy source, in combination with a gauze pad and a resilient non-conductingholder ring which holds the gauze pad firmly inelectrical contact with the electrode disc. The gauze pad is suitable for receiving saline or another liquid solution having high conductive properties, and

preferably has a disctshaped metal plate attached to one surface thereof which is placed against the metal electrode disc, the metal plate providing structure which maybe reliably held by the holder ring. The holder ring has annular receiving grooves which receive the electrode disc and metal plate respectively, and holds them in clamped contact with each other. In

the preferred embodiment, the non-conductive holder ring-isinitially connected to the gauze pad, the defibrillating electrode in turn being clamped into the holder ring to form the operative device. In an alternate embodiment, the holder ring may be initially connected to the electrode, in-which case the gauze pad is inserted into the holder ring to form the operative device. In clinical use of the apparatus, the gauze pad is soaked with-saline oran equivalent conducting solution, and the entire apparatus is positioned directly upon the patient.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross sectional view of the preferred embodiment of the invention, showing the defibrillation DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, a standard defibrillator electrode 20 is shown having a handle 21 made of a non- .conductive material, such as plastic or wood, and having -.a mounting disc 22 also constructed of a nonconducting material. A metallic electrically conducting electrode disc 24, of lesser radius than mounting disc 22, is mounted on the under side of mounting disc 22, and is connected to an electrical source, not shown, through insulated leads 25 which extend through handle 21. Disc 24 is adjacent to and in contact with metal plate 26 which in turn is in clamped connection with gauze pad 27. Metal plate 26 is preferably of small thickness, but thick enough to provide structural rigidity. It may be fabricated of any convenient and economical conducting material which has excellent conducting properties, such as aluminum or steel, or various alloys.

The gauze pad 27 is primarily of circular construction, having a thickness sufficient to readily absorb saline solution, or another appropriate conducting liquid, and to be impressed upon the contour of the patients chest such that substantially all of the lower surface of the pad is in contact with the chest. The pad is held firmly to metal plate 26 by outer tab portions 28 which are turned approximately 180 radially inward, thereby crimpingly engaging pad 27 and holding it firmly to plate 26. The radially outward portions 29 of plate 26, which extend between the notched spaces from which the tabs are bent, are available for providing support of the entire gauze pad structure, as is explained below.

The gauze pad 27 is supported through plate 26 which in turn is held in annular holder ring 30. Holder ring 30, also seen in FIG. 3, is made of a resilient nonconducting material, preferably a commercially available plastic. Annular parallel receiving grooves 32 and 33 in the ring having thicknesses matching the thicknesses of support plate 22 and metal plate 26 respectively. The radius of each groove is just slightly in excess of the radius of each member to be received therein, providing for a snug and tight fitting.

Gauze pad 27 is attached to ring 30 by fixedly attaching outer portions 29 into groove 33 of the ring. This insertion may be made, for example, by raising the center of plate 26 to contract the effective diameter of the plate, inserting the portions 29 into groove 33, and then relaxing the plate so that portions 29 wedge into groove 33. The thickness of portions 29 may be made equal to or slightly greater than the thickness of groove 33, to ensure a tight engagement. Plate 22 may then be inserted into groove 32 by simply centering the plate within the opening of ring 30, and pressing down firmly until the plate snaps into groove 32. To aid in such placement, the upper inner edge of ring 30 has been beveled as in 31, and the outer edge of plate 22 has been given a parallel bevel as at 23. The resiliency of ring 30 permits the outward pushing of the ring to allow placement of plate 32, and ensures that the ring 30 will snap back to firmly hold plate 22 in position.

With the gauze pad and the electrode firmly mounted in the ring, as in FIG. I, an operable unit is obtained having the benefits of the saline soaked pad, but without the present limitations of using such pads. A good electrical path to the patient is ensured, the conductive path being through leads 25 to electrode disc 24, from disc 24 to plate 26, and from plate 26 through the gauze pad 27 which is firmly impressed against the patients chest. In order to ensure good contact between plate 26 and electrode 24, plate 26 may be constructed with a slight outward convex bias, such that when plate 22 is snapped into the ring 30, it forces down against plate 26, pressing it out flat as shown, and ensuring good contact therewith. Alternately, plate 26 may be fabricated with upward-projecting dimples on its surface, to ensure good contact.

In operation, the gauze pad is preferably supplied to the user already connected to a ring 30. At any time' prior to the operating procedure where defibrillation might be necessary, the electrode is clamped into the ring, providing the integral electrode unit with a gauze pad. At time of use, saline solution is applied to the gauze pad, and the entire electrode unit impressed directly onto the patient. Thus, the device enables a two step procedure, namely that of applying saline solution to the gauze pad, and impressing the electrode directly onto the patient. By contrast, the present clinical procedure requires the steps of applying saline solution to a separate gauze pad, applying the gauze pad to the patient, and then impressing the electrode on top of the gauze pad. Further, with this invention, after the discharge of electricity through the electrode, the electrode is simply withdrawn, whereas in present procedures, after the electrode is withdrawn, the gauze pad must be picked off of the patient and thrown away. In the event of recurrence of fibrillation, the user of our apparatus need only re-soak the gauze pad with solution and, indeed, if a recurrence follows in a short enough time, it would not even be necessary to reapply saline solution to the gauze pad.

In the preferred embodiment as shown, the ring is designed so that the gauze pad is first connected to the ring, and the electrode is then clamped into the ring from above. It is understood that the structure can be modified to permit insertion of either the electrode or the gauze pad from above or from below. Further, alternate forms of the plate 26 may be used with this invention. Since plate 26 serves the primary function of providing a rigid structure which can be clamped into ring 30, it need not be solid throughout. A screen or mesh, having as illustrated in FIG. 4, sufficient rigidity around the outer periphery where it is inserted into groove 33, would be equally functional for holding the gauze pad to the ring, and for providing good electrical contact between the pad and electrode disc 24.

It is noted further that the gauze pad may be packaged in a saline-moistened condition within a watertight package, such as the commercially available package used for wet towels and the like. In this form, the user need only rip off the outer portion of the gauze pad package to expose the soaked pad, and apply directly to the patients chest.

We claim:

1. Defibrillation electrode apparatus for applying electrical shock energy to a patient, comprising:

a. an electrode disc having opposite surfaces;

b. a support plate integrally connected to a first of said disc surfaces;

c. gauze means for receiving and holding a conductive solution, having a support surface in contact with the second surface of said electrode, said support surface having outer tab portions turned radially inward so as to hold said gauze means in crimped engagement with said plate and also radially outward extending portions;

d. annular clamping means for holding said disc and said gauze means in clamped engagement such that good electrical contact is maintained between said disc and said gauze means; and

e. a handle connected to said support plate having insulated leads extending therethrough and connecting to said disc, through which defibrillation shock energy can be transmitted.

2. The apparatus as described in claim 1 wherein said annular clamping means contains a first annular groove which receives said support plate, and a second annular groove which receives said radially outward extending portions, and is composed of a resilient and nonconducting material.

3. The apparatus as described in claim 2 wherein said support surface comprises a screen, the outer periphery of which is received and held in said annular clamping means. 

1. Defibrillation electrode apparatus for applying electrical shock energy to a patient, comprising: a. an electrode disc having opposite surfaces; b. a support plate integrally connected to a first of said disc surfaces; c. gauze means for receiving and holding a conductive solution, having a support surface in contact with the second surface of said electrode, said support surface having outer tab portions turned radially inward so as to hold said gauze means in crimped engagement with said plate and also radially outward extending portions; d. annular clamping means for holding said disc and said gauze means in clamped engagement such that good electrical contact is maintained between said disc and said gauze means; and e. a handle connected to said support plate having insulated leads extending therethrough and connecting to said disc, through which defibrillation shock energy can be transmitted.
 2. The apparatus as described in claim 1 wherein said annular clamping means contains a first annular groove which receives said support plate, and a second annular groove which receives said radially outward extending portions, and is composed of a resilient and non-conducting material.
 3. The apparatus as described in claim 2 wherein said support surface comprises a screen, the outer periphery of which is received and held in said annular clamping means. 